One person has been arrested in the case relating to the death of a pregnant wild elephant in Kerala, the state forest department said on Friday.

'KFD has zeroed in on the culprits and recorded the first arrest in the wild elephant death case', the department said in a tweet.

The incident had triggered a national outrage.

Forest department sources had said yesterday that three people were under the scanner of the joint investigation team of Kerala police and their personnel and a search was on for two more people.

Personnel of Kerala police and the forest department's Crime Investigation Team, probing the incident which triggered widespread outrage especially on social media, visited the spot and collected evidence, state chief minister Pinarayi Vijayan said on Thursday, assuring that all concerns raised will not go in vain and justice will prevail and the culprits brought to book.

Forest department sources told PTI that the three suspects were being questioned and a search was on for two more people in connection with the death of the elephant on May 27.

The 15-year-old elephant is suspected to have consumed a pineapple filled with powerful fire crackers which exploded in the animal's mouth in the Silent Valley Forest and it died in Velliyar River about a week later.

Vijayan's assurance of stern action came amid a social media storm over the brutality meted out to the elephant and the Centre expressing serious concern

The state forest department had in a tweet said 'There is no conclusive evidence that injury to lower jaw was caused by pineappple stuffed with crackers. However, this may be a possiblity'.

A case has been registered under Wild Life (Protection) Act. Explosives Actand Prevention of Cruelty to Animals Act.

'In the offence registered as per the sections of WL (P)A for hunting the elephant, several suspects are being interrogated. SIT formed for the purpose is making a significant headway in this regard. Forest Dept will leave no stone unturned to ensure max punishment to the offenders,' the department said in a tweet.

It clarified the 'place where the unfortunate incident took place falls in Palakkad district, and not in Malappuram district as reported in some sections of the media'.

The pachyderm's tragic end came to light after a forest officer posted an emotional note on his Facebook page, narrating it.

It died in the Velliyar River a week later on May 27.